A stepping motor has been conventionally used as a motor in an optical pickup device which is used in a CD player and a DVD player or as a motor for moving a lens group used in a camera. As this type of a stepping motor, a stepping motor which is provided with pole teeth fixed to an outer yoke and pole teeth fixed to an inner yoke has been known (see, for example, Patent Literature 1).
In the stepping motor described in Patent Literature 1, the pole teeth fixed to the outer yoke and the pole teeth fixed to the inner yoke are alternately disposed in a circumferential direction of the rotor and the pole teeth are disposed so as to face an outer peripheral face of a drive magnet structuring the rotor. Further, in the stepping motor, the pole teeth are formed in a roughly trapezoid shape and spaces in the circumferential direction between the pole teeth fixed to the outer yoke and the pole teeth fixed to the inner yoke are set to be constant in an axial direction of the rotor.